Stranding apparatus and method



1965 R. E. CORRALL. ETAL 3,169,360

swamnmc APPARATUS AND METHOD 3 Sheets-Sheet 1 Filed July 2, 1962 ML .LmA mm v mm B Y O R GEORGE N. MENASO FF Feb. 116,.v 1965 R. E. CORRALL,ETAL S'IRANDING APPARATUS AND METHOD 3 Sheets-Sheet 2 Filed July 2, 1962F C- m O TAW m M R V ON w 0E RG 17/5/19 Mil/i 6 R. E. CORRALL ETAL 3,

STRANDING APPARATUS AND METHOD Filed July 2, 1962 3 Sheets-Sheet 3INVENTORS ROY E. COR R ALL GEORGE.N. MENASOFF United States Patent Ourinvention relates to strand twisting and particularly-to the twisting ofstrand with a false 'or reversing I twist.

In the stranding of insulated conductors there are certain advantages totwisting the strands in afalse twist with periodicreversals of directionof lay rather than twisting them in a continuous helix in the mannermost commonly practiced. Amongfthese advantages are the 'facts that inapplying a false twist it is not necessary to rotate the take-up orpay-off assembly and the expensive equipment necessary for the rotationof heavy reels can be eliminated. With the elimination of heavy rotatingelements comes the additional advantage of increased speed of operation.There, are also advantages in the false twisted product itself in thatslack can be generated in short lengths of such strand merely byuntwisting a central length of it even when the ends are remote, withoutany necessity for cutting the conductors. A most important advantage,however, from the vantage point of this invention, is that when strandsare twisted with a false twist the stranding operation can be part of acontinuous process involvingsteps both downstream and upstream of thetwisting where the ends of the'strand are not available for rotating.Such a process would occur for instance where conductors are insulatedin an extruder, twisted into pairs, and combined to form a cable. Incontra-distinction to such a proposed process it is present commercialpractice to insulate conductors individually and take them up on reels.The insulated conductors on two of the reels are then twisted into pairsand taken up on reels again. Finally the pairs on a plurality of thesereels are stranded into a cable. It has been known to apply a falsetwist by passing filaments through a reciprocating lay plate but theangle of such twists has been limited to a fraction of a full turnbecause of the tangling of strands upstream of the lay plate and in nocase has been able to exceed 540.

to advancing strand comprising means accumulating such strand which maybe, but is not necessarily limited to,

a sheave, a roll supporting a plurality of turns or a pair of rollssupporting at least one loop and mounted in a cradle, and alsocomprising means for rotating the accumulating means, such as byrotating thecradle, so as an impart a twist of one direction to thestrand leaving the accumulating means, and a twist of opposite directionto the strand entering the accumulating means. Our apparatus alsocomprises means for alternately restraining the accumulating meansagainst rotating for a period sufficient to advance the twisted strandfrom it, and may also comprise means for binding the strand, preferablyat reversal points while leaving the strand free from binding elsewhere.Such binding may be quicksetting cement such as but not limited to thehot-melt adhesive such as that described in application Serial Number190,108, filed April 25, 1962, and assigned to the assignee of thisinvention.

Where reverse-lay or false twisting has been used 7 for the stranding ofprior art electric cables it has not been known to twist more than afraction of a turn between reversals. We have invented reverse twistcables with angles of twist in excess of 540 and even in excess of threeor more complete turns. These may be but are not limited to telephoneconductor pairs of two insulated wires or multi-pair cables comprising aplurality of such twistedpairs with a jacketoverall. Our cables may bemade with reverse twistingof the strands, and binding at the points ofreversal, the strands being free from bindingelsewhere along theirlengths; and the binding may be a hot-melt adhesive;

I We have also invented a method of twisting a strand comprisingcontinuously advancing it into an accumulated supply of strand whilesimultaneously paying the strand from the supply and periodicallyrotating the supply to impart a twist to the strand leaving the supply,and an opposite twist to the strand entering thesupply. In our methodthe supply is preferably alternately restrained against the rotating orrotated in the opposite direction until the twisted strand has paid fromit and the angle of rotation is in excess of 540 and preferablyencompasses a plurality of full turns. Our method also preferablycomprises the step of binding the strand intermittently at reversalpoints as by a hot-melt adhe-v sive, which binding may advantageouslyoccur as the first step in our process. A more thorough understanding ofour invention can be obtained from a study of the appended drawing.

In the drawing:

. FIGURES 1a and 1b are perspective views of an apparatus made to ourinvention.

FIGURE 2 is a perspective view of an adhesive applicator used in oneembodiment of our invention.

FIGURE 3 is a lengthwise view of a twisted strand of our invention. V

FIGURE 4 is a lengthwise, cut-away view of a cable of strands of ourinvention.

' Referring to FIGURES 1a and lb a stranding apparatus, indicatedgenerally by the numeral 10 is mounted on a base 11. A strand 12comprised of parallel insu lated conductors 13, 14 is advancing fromright to left as seen in the drawing from a supply source not shown. Ourapparatus has particular utility for the twisting of telephone cablepairs such as may be made from the insulated conductors 13, 14 but itcan also be advantageously used for quads and for other types of strandcomprising a greater or fewer number of conductors or other filaments;The strand 12 passes through a binding head 16 where it is boundtogether at fixed intervals along its length. We have shown a known typeof commercially available binding head of which the wire andharnesstaper made by the Possis Machine Corp 825 Rhode Island Avenue,Minneapolis 26, Minn,

is an example. In this embodiment of the binding head 16 a gummed tape17 feeds from a pad 18 and a short length of the tape is automaticallywrapped around the strand at selected intervals. Since our strand 12 iscontinuously advancing we have mounted the binding head 16 on rails 19so that it can be advanced at the speed of advancement of the strand 12by the rotation of a worm 21 driven by a reversing motor 22. After thestrand 12 has been bound at one point, the motor 22 reverses to turn theworm 21 in the opposite direction so that the head 16 is returned to itsoriginal position. This is quite feasible in our apparatus because thelong lengthof strand between reversal points allows ample time for thereturn of the head 16, and it constitutes one of 'the advantages of ourinvention. Although we have shown a' binding head 16 which wraps gummedtape around the strand it will be readilyunderstood that we do not wishto be limited to this method of binding. For instance, in FIGURE 2, wehave shown a binding means hereinafter to be explained in detail, whichutilizes hot-melt or other quick-setting adhesive for bindingour strand12. As the strand pays from the binding head 16 it passes through ahollow journal 23 which turns in a bearing 24 mounted on a pedestal 26,which is in turn supported on the base 11. Also mounted on the base 11another pedestal 27 is surmounted by a bearing 28 in which anotherhollow journal 29 rotates in line ,with the journal 23. The journals 23,29 support between them a cradle 31, which we prefer to form from asingle bar 32 for ease in stringing, as shall be shown. The bar 32mounts an upper rigid bearing 33 which supports a grooved roll 34 on acantilevered shaft 36., The roll 34 is wide enough to contain aplurality of grooves 37 and it will be understood the greater the numberof grooves 37, other factors being equal, the greater will be thestorage capacity of our apparatus. It is, however, contemplated that forsome applications the roll 34 may have a single groove and take the formof a simple sheave. Upstream and to the right of the bearing 33, abearing 38 is mounted on the underside of the bar 32. The bearing 38supports a light-Weight flanged roll 39 on a cantilevered shaft 41. Theroll 39 is wide enough to accommodate all the turns of strand supportedby the grooves 37 and the strand is formed in a plurality of loops 42enclosing the two rolls 34, 39. The rolls 34 and 39 are of verylight-weight construction so that they are easily turned by the forwardmotion of the strand 12 but it will be understood that where the strandmight be broken or damaged by the load incurred in turning them, therolls 34 and 39 may be driven by gear trains or other means known topersons skilled in mechanical arts.

Before entering upon the roll 39 the strand 12 passes through a pair ofpinch rolls 43, 44 mounted on a bar 46 fixed to the base 11 by means ofa pedestal 47. Thus the pinch rolls 43, 44 remain stationary and do notrotate along with the cradle 31 and are tight enough to prevent backtwist in the strand 12. In the embodiment of our apparatus shown inFIGURES la and 1b the strand 12 makes one turn around the roll 39adjacent to the near flange, and then passes around the grooved roll 34and back to the roll 39 to form the series of loops 42. Leaving the roll34 the strand passes over guide sheaves 48, 49 through another pair ofpinch rolls 51, 52 and thence to take-up means not shown, which mayincorporate another processing step. The pinch rolls 51, 52 are fixed toa bar 53 rigidly mounted to the base 11 by means of a pedestal 54. Abelt pulley 56 is locked to the journal 23 and is driven through a belt57 by means of a drive pulley 58 and motor 59 which we prefer to be ahigh-inertia rotor motor. The pulley 58 is connected to a shaft 61 ofthe motor 59 through a clutch 62 and can be stopped by an electric brake63. The clutch 62 and brake 63 are actuated by a limit switch 64 throughbrushes 66, 67 and slip rings 68, 69. The limit switch 64 is, in turn,actuated by a cam 71 driven at a selected reduction ratio from the roll39. In the apparatus shown we prefer to employ a reduction ratio of 20to 1, operating in a known manner so that the drive pulley 58 will bestopped by the disconnection of the clutch 62 and application of thebrake 63 after twenty revolutions of the roll 39,

and will start again after another twenty revolutions, and so on. Thusthe cradle 31 is caused to rotate for a period equal to twentyrevolutions of the roll 39 and alternately to remain stationary fortwenty revolutions. In this regard it should be particularly noted thatin one method of operation of our apparatus the rolls 34 and 39 rotatecontinuously at a constant rate and the motor 59 runs continuously inthe same direction; the cradle 31, although it stops and starts atregular intervals does not reverse its direction of rotation but rotatesalways in the same direction. In another method of operation the clutch62 is a reversing clutch and the cradle 31 rotates alternately fortwenty revolutions clockwise and counterclockwise.

A second limit switch 72 is connected through slip rings 73, 74 andbrushes 76, 77 and wires 78, 79 there- (it from to the binding head 16so that the binding head applies binding to the strand once for everytwenty revolutions of the roll 39. The switch 72 is actuated by a cam 75driven by a reducing mechanism from the roll 39. The cams 71 and 75 turnat equal rates of speed but are out of phase to an extent selected sothat a bound point in the strand 12 reaches the pinch rolls 43, 44

each time the rotation of the cradle 31 stops or starts.

It will be understood that although we have selected a length of twentycircumferences of the roll 39 as the length of strand between reversalpoints other lengths can also be chosen within the scope of ourinvention, but the length should correspond to the length of strandstored on the rotating cradle 31 between the pairs of pinch rolls 43, 44and 51, 52. In the illustrated case this length is just twentycircumferences of theroll 39.

Although we have preferred to apply binding to our strand 12 upstream ofits entrance into the storage rotating means our invention also willinclude apparatus Where the binding head is mounted downstream of thecradle and applies binding to strand emerging from the pinch rolls 51,52. Such a binding might be applied continuously as by winding with ayarn or tape, or it might be applied only at points of reversal. Theextent of binding required depends to some extent on the springiness ofthe strand being twisted. We have found that polyethylene-insulated,solid-copper telephone conductor pairs can be twisted verysatisfactorily on the apparatus described and shown in FIGURES 1a and1b. Where the springiness of the strand is such that the false twisttends strongly to unwind under very slight tension this unwinding mighttake place in the unsupported portions of the loops 42 between the rolls34 and 39. This can be overcome at the expense of storage capacity byhaving only a single roll such as the roll 39 mounted on the cradle 31so that the stored strand will, at all times, be restrained fromunwinding by it's frictional contact with the surface of the roll. Ifthe strand is then bound continuously as it leaves the cradle, even aspringy strand will retain its false twist.

Operation grooves 37 in the roll 34 and also the roll 39 until all thegrooves 37 have been used. This stringing of the strand 12 is greatlysimplified by the cantilever mounting of the rolls 34 and 39. Thethreading of the strand continues over the sheave 48 and under thesheave 49, through the final rolls 51, 52 and downstream to the take-upapparatus, not shown. It will be understood that, in order to avoidwaste, all or part of this threading may employ a piece of scraplead-cord that can be discarded later.

The motor 59 is operated with the clutch 62 engaged and the brake 63released so that the cradle 31 rotates as the strand 12 pays through theapparatus. As the cradle rotates it applies a twist to the strand 12 atthe pinch rolls 51, 52 so that the strand advancing downstream of theapparatus is twisted. At the same time, the strand 12 entering theapparatus through the pinch rolls 43, 44 is given a twist in theopposite direction to the twist imparted by the pinch rolls 51, 52. Asthe stranding progresses the untwisted strand that was initially storedon the rolls 34, 39 is twisted as it pays off through the pinch rolls51, 52 While the fresh strand being taken up in the storage is twistedat the rolls 43, 44 and stored in the twisted condition. When twentycircumferences of the roll 39 have been pair into the apparatus all theuntwisted strand will have advanced from the storage and will have beenreplaced by twisted strand. At this point the cam 71 will actuate theswitch 64 to disengage the clutch 62 and apply the brake 63 thusstopping rotation of the cradle 31.

However, the strand 12 will continue to pay through. the pinch rolls 51,52, but since all the stored strand is twisted in a direction oppositeto the strand already advanced there will be a point of reversal in'thestrand passing through the rolls 51, 52 at the time the cradle stopsrotating. As the twisted strand continues to advance from the stationarycradle it is replaced by untwisted strand passing through the rolls 43,44. When the twisted strand is completely replaced by untwisted strandthe clutch 62 will engage and the cradle will start to rotate and thusrepeat the cycle. During this operation the binder head 16 is, applyinga gummed-tape binding to points of the strand which correspond to pointsof reversal of twist with the result that the false twist does notunwind when the strand emerges from the apparatus. When, instead ofremaining stationary at the end of each cycle, the cradle 31 rotatesalternately clockwise and counterclockwise, the strand taken up in thestorage is always twisted and an additional twist in the same directionis applied to the strand as it leaves the storage.

During the initial loading of the storage with twisted strand (andduring each of the subsequent periods between reversal points) thecradle will make a plurality of complete revolutions: For example, ifthe length of twist-lay is six inches and the circumference of the roll39 is one foot there will be forty full turns in the strand betweenreversal points. This large number of turns has a number of importantadvantages. For one thing it reduces the number of bindings requiredwhere the bindings are applied only at reversals. It provides ample timefor the return of the binding head. It prevents the false twist beingunwound by tension in the strand. And it reduces the frequency ofstarting and stopping of rotation of the cradle.

In a preferred embodiment of our invention, binding of the strand isaccomplished by an apparatus 100 shown in FIGURE 2. In this apparatusthe conductors l3, 14 pass through respective separating guide blocks161, 102 mounted on a platform 103 on a pedestal 194 on the base 111.Also mounted on the platform M3 is a solenoidcnntrolled nozzle 105 towhich is supplied a suitable hotmelt, or other quick-setting cement suchas that hereinbefore described through an insulated pipe-line 106 from asource not shown. The nozzle W5 is activated by the switch 72 throughthe lead wires '78, '79 to apply a deposit of cement to the wire 14% atpoints corresponding to points of reversal of the twist, immediatelyafter which, the conductors l3, 14 pass between grooved pinch rolls 187,MP3 where they are brought together and bound by the cement. From therolls 107, 108 the strand passes through the hollow journal 23 and isprocessed as hereinbefore described.

The length of the conductor 14 to which cement canbe continuouslyapplied by this method is not limited and this provides for somelatitude in obtaining perfect registration between the point of bindingand the point of reversal of twist. Alternatively, it is within thescope of our invention to mount the apparatus lltlil downstream of thecradle Fall to bind the strand after it has been twisted.

In FIGURE 3 we have shown a paired strand 110 twisted in accordance withour invention. The strand is comprised of insulated conductors 113, 114which can be seen to have a right-hand twist at a length 116 and aleft-hand twist at a length 117. Reversal points occur at 11%, 119, 121and in between these reversals the twist in the strand continues in onedirection for a large plurality of turns. At the reversal pointsbindings 122, 123, 124, which consist in this embodiment of hot-meltadhesive, prevent the strand from opening. Although we have shownbinding only at reversal points in might be continued for a longerdistance within the scope of our invention, and instead of a hot-meltcement might consist of other adhesive means, or of wraps of adhesivetape or continuous servings of yarn or tape.

6 In FIGURE' 4 a plurality of the paired strands have been formed into acable 126 with a jacket 127.

We have invented a new and useful apparatus and method for which wedesire an award of Letters Patent.

We claim: v 1. Apparatus applying a reversing twist to advancing strandcomprising:

. (A) means accumulating said strand comprising (a) a sheave and V (b) acradle mounting said sheave, said cradle being fixed against translationalong the axis of advance of said strand, and

(B) means alternately (a) rotating said cradle so as to impart a twistof one direction to said strand leaving said sheave and a twist ofopposite direction to said strand entering upon said sheave, and

(b) restraining said cradle from rotation for a period sufiicient toadvance said strand having said opposite twist around the circumferenceof said sheave.

2. Apparatus applying a reversing twist to advancing strand comprising:p g V (A) means accumulating said strand comprising (a) a'rollsupporting a plurality of turns of said strand and (b) a cradle mountingsaid roll,'said cradle being fixed against translation along the axis ofadvance of said strand, and

(B) means alternately (a) rotating said cradle so as to impart a twistof one direction to said strand leaving said roll and a twist ofopposite direction to said strand entering upon said roll, and

(b) restraining said cradle from rotation for a period suflicient toadvance said strand having said opposite twist around said plurality ofturns.

3. Apparatus applying a reversing twist to advancing strand comprising:

(A) means accumulating said strand comprising (a) a pair of rollsmounted on parallel axes and supporting at least one loop of saidstrand,

(b) a cradle mounting said rolls, said cradle being fixed againsttranslation along the axis of advance of said strand, and

(B) means alternately (a) rotating said cradle so as to impart a twistof one direction to said strand leaving said rolls and a twist ofopposite direction to said strand entering upon said rolls, and

(b) restraining said cradle from rotation for a period sufiicient toadvance said strand having said opposite twist from said rolls.

4. Apparatus applying a reversing twist to advancing strand comprising:

(A) means accumulating said strand comprising (a) a pair of rollsmounted on parallel axes and supporting at least one loop of saidstrand,

(b) a cradle mounting said rolls, said cradle being fixedagainst'translation along the axis of advance of said strand, and

(B) means alternately (a) rotating said cradle so as to impart a twistof one direction to said strand leaving said rolls and a twist ofopposite direction to said strand entering upon said rolls, and

(b) restraining said cradle from rotation for a period sufiicient toadvance said strand having said opposite twist from said rolls, therebyimparting to said strand periodic points of reversal of twist, and

(C) means applying binding to said strand at said points of reversal,said strand being free from binding elsewhere along said strand.

7 5. Apparatus applying a reversing twist to advancing strandcomprising:

(A) means accumulating said strand comprising (a) a sheave, ([2) acradle mounting said sheave, and (c) a pair of pinch rolls mounteddownstream of said sheave, said cradle and said pinch rolls being fixedagainst translation along the axis of advance of said strand, and (B)means alternately (a) rotating said cradle so as to impart a twist ofone direction to said strand between said sheave and said pinch rolls,and a twist of opposite direction to said strand entering upon saidsheave, and (b) restraining said cradle from rotation for a periodsuflicient to advance said strand having said opposite twist around thecircumference of said sheave. 6. Apparatus applying a reversing twist toadvancing strand comprising:

(A) means accumulating said strand comprising (a) a roll supporting aplurality of turns of said strand, (b) a cradle mounting said roll, and(c) a pair of pinch rolls mounted downstream of said roll, said cradleand said pinch rolls being fixed against translation along the axis ofadvance of said strand, and (B) means alternately (a) rotating saidcradle so as to impart a twist of one direction to said strand betweensaid roll and said pinch rolls and a twist of opposite direction to saidstrand entering upon said roll, and (b) restraining said cradle fromrotation for a period sufiicient to advance said strand having saidopposite twist around said plurality of turns. 7. Apparatus applying areversing twist to advancing strand comprising:

(A) means accumulating said strand comprising (a) a pair of storagerolls mounted on parallel axes and supporting a plurality of loops ofsaid strand, (b) a cradle mounting said rolls, and (c) a pair of pinchrolls mounted downstream of said storage rolls, said cradle and saidpinch rolls being fixed against translation along the axis of advanceofsaid strand, and (8) means alternately (a) rotating said cradle so asto impart a twist of one direction to said strand between said storagerolls and said pinch rolls and a twist of opposite direction to said.strand entering upon said storage rolls, and (b) restraining said cradlefrom rotation for a period suflicient to advance said strand having saidopposite twist from said storage rolls. 8. Apparatus applying areversing twist to advancing strand comprising:

(A) means accumulating said strand comprising (a) a pair of storagerolls mounted on parallel axes and supporting a plurality of loops ofsaid strand, (II) a cradle mounting said rolls, and (c) a pair of pinchrolls mounted downstream of said storage rolls, said cradle and saidpinch rolls being fixed against translation along the axis of advance ofsaid strand, (B) means alternately (a) rotating said cradle so as toimpart a twist of one direction to said strand between said storagerolls and said pinch rolls and a twist of opposite direction to saidstrand entering upon said storage rolls, and

(b) restraining said cradle from rotation for a period sufficient toadvance said strand having said opposite twist from said storage rollsthereby imparting to said strand periodic points of reversal of twist,and

(C) meansapplying binding to said strand at said points of reversal,said strand being free from binding elsewhere along said strand.

9. Apparatus applying a reversing twist to advancing strand comprising:

(A) means continuously accumulating and paying oil supplies of saidstrand,

(B) means alternately rotating said accumulating means in one directionuntil one said supply has paid off and in the reverse direction untilthe next said supply has paid on thereby giving said strand periodicpoints of reversal of twist, and

(C) means applying binding to said strand at said points, said strandbeing free from binding elsewhere along said strand.

10. The apparatus of claim 9 wherein said accumulating means comprisesat least one roll mounted in a cradle.

11. The method of twisting a strand comprising the steps of: I

(A) continuously advancing said strand into an accumulated supply ofsaid strand,

(B) simultaneously paying said strand from said accumulated supply and(C) during said advancing, alternately (a) rotating said accumulatedsupply so as to (1) impart a twist to said strand leaving said supply,and (2) impart an opposite twist to said strand entering said supply,and (b) restraining said supply against said rotating until saidoppositely twisted strand has paid from said supply.

12. The method of twisting a strand comprising the steps of:

(A) continuously advancing said strand into an accumulated supply ofsaid strand,

(B) simultaneously paying said strand from said accumulated supply, and

(C) during said advancing, alternately (a) rotating said accumulatedsupply through an angle in excess of 540 so as to (1) impart a twist tosaid strand leaving said supply, and (2) impart an opposite twist tosaid strand entering said supply, and (b) restraining said supplyagainst said rotating until said oppositely twisted strand has paid fromsaid supply.

13. The method of twisting a strand comprising the steps of:

(A) continuously advancing said strand into an accumulated supply ofsaid strand,

(B) simultaneously paying said strand from said supply, and

(C) during said advancing, alternately (a) rotating said accumulatedsupply through an angle in excess of 540 so as to impart a twist to saidstrand leaving said supply and an opposite twist to said strand enteringsaid supply, and

(b) restraining said supply against said rotating until said oppositelytwisted strand has paid from said supply, and

(D) binding said strand intermittently at points of reversal of saidtwist.

14. The method of twisting a strand comprising the steps of:

(A) applying binding to said strand at regularly spaced intervals whilecontinuously advancing said strand,

9' I (B) collecting said strand in an accumulatedsupply thereof, (C)simultaneouslycontinuously paying said strand from said supply, (D)during said advancing, alternately (a) rotating said supply through anangle in excess of 540 so as to impart a twist to said strand leavingsaid supply and an opposite twist to said strand entering said supply,

(b) restraining said supply against said rotating until said oppositelytwisted strand has paid from said supply,

(c) said restraining being instituted at thetime 'a bound portion ofsaid strand is entering said supply whereby reversals of twist in saidstrand will occur at the bound portions of said strand.

15. The method of twisting a strand comprising the steps of:

(A) continuously advancing said strand into an accumulated supply ofsaid strand, (B) simultaneously paying said strand from said accumulatedsupply, and (C) during said advancing, alternately (a) rotating saidaccumulated supply in one direction so as to (1) impart a twist to saidstrand leaving said supply, and (2) impart an opposite twist to saidstrand entering said supply, and

(b) rotating said accumulated supply in the opposite direction untilsaid oppositely twisted strand has paid from said supply.

16. Apparatus applying a reversing twist to advancing strand comprising:

(A) strand accumulating means (a) mounted for rotation about the axis ofadvance of said strand and (b) fixed against translation along saidaxis, and

(B) means periodically rotating said accumulating means so as to (a)impart a twist of one direction to said strand leaving said accumulatingmeans, and

(b) a twist of opposite direction to said strand entering saidaccumulating means.

17. Apparatus applying a reversing twist to advancing strand comprising:

(A) strand accumulating means (a) mounted for rotation about the axis ofadvance of said strand and (b) fixed against translation along saidaxis, and

(B) means alternately (a) rotating said accumulating means so as toimpart a twist of one direction to said strand leaving said accumulatingmeans and a twist of opposite direction to said strand entering saidaccumulating means, and

(b) restraining said accumulating means from said rotating for a periodsufiicient to advance said strand having said opposite twist from saidaccumulating means.

18. Apparatus applying a reversing twist to advancing strand comprising:

(A) strand accumulating means (a) mounted for rotation about the axis ofadvance of said strand and (b) fixed against translation along saidaxis, and

(B) means alternately (a) rotating said accumulating means so as toimpart a twist of one direction to said strand leaving said accumulatingmeans and a twist of opposite direction to said strand entering saidaccumulating means, and

(b) restraining said accumulating means from said rotating for a periodsufiicient to advance said 19 strand having said opposite twist fromsaid accumulating means, and (C) means applying binding to said strand,thereby restraining said twist. 19. Apparatus applying a reversing twistto advancing strand comprising:

(A) strand accumulating means (a) mounted for rotation about the axis ofadvance of said strand and (b) fixed against translation along saidaxis,and (B) means alternately a (a), rotating said accumulating means so asto impart a twist of one direction to said strand leaving saidaccumulating means and a twist of opposite direction to said strandentering said accumulating means, and (b) restraining said accumulatingmeans from said rotating for a period sufiicient to advance said strandhaving said opposite twist from said accumulating means thereby givingsaid strand periodic points of reversal of twist, and (C) means applyingbinding to said strand at said points, said strand being free frombinding elsewhere along said strand. 20. Apparatus applying a reversingtwist to advancing strand comprising:

(A) means accumulating said strand, (B) means alternately (a) rotatingsaid accumulating means so as to impart a twist of one direction to saidstrand leaving said accumulating means and a twist of opposite directionto said strand entering said accumulating means, and (b) restrainingsaid accumulating means from said rotating for a peniod sufiicient toadvance said strand having said opposite twist from said accumulatingmeans thereby giving said strand periodic points of reversal of twist,and (C) means applying a quick-setting adhesive binding to said strandat said points, said strand being free from binding elsewhere along saidstrand. 21. Apparatus applying a reversing twist to advancing strandcomprising:

(A) means accumulating said strand comprising (a) a pair of rollsmounted on parallel axes and supporting at least one loop of saidstrand, (b) a cradle mounting said rolls, and (B) means alternately (a)rotating said cradle so as to impart a twist of one direction to saidstrand leaving said rolls and a twist of opposite direction to saidstrand entering upon said rolls, and (b) restraining said cradle fromrotation for a period suificient to advance said strand having saidopposite twist from said rolls, thereby imparting to said strandperiodic points of reversal of twist, and (C) means applying aquick-setting adhesive binding to said strand at said points ofreversal, said strand being free from binding elsewhere along, saidstrand. 22. Apparatus applying a reversing twist to advancing strandcomprising:

(A) means accumulating said strand comprising (a) a pair of storagerolls mounted on parallel axes and supporting a plurality of loops ofsaid said strand, (b) a cradle mounting said rolls, and (c) a pair ofpinch rolls mounted downstream of said storage rolls, (B) meansalternately (a) rotating said cradle so as to impart a twist of onedirection to said strand between said storage rolls and said pinch rollsand a twist of opposite direction to said strand entering upon saidstorage rolls, and

1 1 (b) restraining said cradle from rotation for a period suflicient toadvance said strand having said opposite twist from said storage rollsthereby :imparting to said strand periodic points of reversal of twist,and (C) means applying quick-setting adhesive binding to said strand atsaid points of reversal, said strand being free from binding elsewherealong said strand.

References Cited in the file of this patent UNITED STATES PATENTS1,030,426 Parsons et a1. June 25, 1912 1,960,426 Zundorf May 29, 19342,001,065 Klein May 14, 1934 Peterson Mar. 23, Berggren et a1. Oct. 12,Speekman June 19, Gillis Apr. 30, Bryan et a1. Apr. 21 Lilly Oct. 11,Lenk et a1. Oct. 25, Crosby et a1. Ian, 16, Cook Mar. 20, Henning Sept.4, Bloch Nov. 6,

FOREIGN PATENTS Denmark Apr. 4,

1. APPARATUS APPLYING A REVERSING TWIST TO ADVANCING STRAND COMPRISING:(A) MEANS ACCUMULATING SAID STRAND COMPRISING (A) A SHEAVE AND (B) ACRADLE MOUNTING SAID SHEAVE, SAID CRADLE BEING FIXED AGAINST TRANSLATIONALONG THE AXISOF ADVANCE OF SAID STRAND, AND (B) MEANS ALTERNATELY (A) AROTATING SAID CRADLE SO AS TO IMPART A TWIST OF ONE DIRECTION TO SAIDSTRAND LEAVING SAID SHEAVE AND A TWIST OF OPPOSITE DIRECTION TO SAIDSTRAND ENTERING UPON SAID SHEAVE, AND (B) RESTRAINING SAID CRADLE FROMROTATION FOR A PERIOD SUFFICIENT TO ADVANCE SAID STRAND HAVING SAIDOPPOSITE TWIST AROUND THE CIRCUMFERENCE OF SAID SHEAVE.